Specifications

ST900 Family General Handbook
667/HB/32900/000 Issue 10 Page 73 of 265
connected to the controller’s handset port, the ST900 controller configuration utility
IC4 loads the configuration data into the controller, negating the need for an
EPROM.
In the UK some timings considered to be fixed timings cannot be changed by
handset, these are typically the Amber and Red/Amber periods. These timings can,
however, be specified as alterable at configuration time to suit other signal
sequences, non UK requirements etc.
Some controller timings are considered to be safety timings and can only be
changed by a person at the controller, e.g. minimum green, inter-greens and
blackout timings. These require the operator to press the ‘level 3’ access button
before attempting to modify these timings.
Following is a summary of some of the timings available within the Siemens Type
900 traffic controller. It also shows their upper and lower limit values and where
applicable the configurable limits. All timings are in seconds unless otherwise
marked.
Lower
Limit
(sec)
Upper
Limit
(sec)
Resol’n
(sec)
Config’ble
Lower Limit
Config’ble
Upper Limit
General Timing Periods
Minimum green
0 255 1 1 per phase 1 per phase
Maximum green (8 sets) 0 255 1 1 value 1 value
Green extension 0.0 31.8 0.2 1 value 1 value
Conflicting phase
change inter-green
0 199 1
1 per change
(32x32)
1 value
RLM 1
st
Red extra inter-green 0 255 1 1 value 1 value
Starting inter-green 0 255 1 1 value 1 value
Red / Amber time
1
0 255 1 1 value 1 value
Leaving Amber time
2
(8 sets) 0 31.8 0.2 1 value 1 value
All red extension 0 31.8 0.2 - -
All red maximum 0 255 1 - -
Phase delay 0 255 1 1 value 1 value
Pedestrian window 0 255 1 - -
Pedestrian Clearance Periods
Fixed Clearance Period 0 255 1 1 value 1 value
Extendable Clearance Period 0 255 1 1 value 1 value
Clearance Red Period 0 255 1 1 value 1 value
1
In the UK, the Red/Amber time is fixed at 2 seconds.
2
In the UK, the Leaving Amber time is fixed at 3 seconds.